"The Grammys have kind of screwed up Valentine's Day for everybody here," the country singer, 34, told PEOPLE at the music-awards show on Sunday. "We're all going to get wasted tonight. I mean, we are. And we're going to feel like crap. The last thing we're going to want to do tomorrow is touch each other."

For her part, Lambert, 27 – who won Best Female Country Vocal Performance for "The House That Built Me" – said she's still expecting Shelton to step up today.